babies_crawl <-
structure(list(birth_month = structure(c(5L, 4L, 8L, 1L, 9L, 
7L, 6L, 2L, 12L, 11L, 10L, 3L), .Label = c("April", "August", 
"December", "February", "January", "July", "June", "March", "May", 
"November", "October", "September"), class = "factor"), avg_crawling_age = c(29.84, 
30.52, 29.699999999999999, 31.84, 28.579999999999998, 31.440000000000001, 
33.640000000000001, 32.82, 33.829999999999998, 33.350000000000001, 
33.380000000000003, 32.32), sd = c(7.0800000000000001, 6.96, 
8.3300000000000001, 6.21, 8.0700000000000003, 8.0999999999999996, 
6.9100000000000001, 7.6100000000000003, 6.9299999999999997, 7.29, 
7.4199999999999999, 5.71), n = c(32L, 36L, 23L, 26L, 27L, 29L, 
21L, 45L, 38L, 44L, 49L, 44L), temperature = c(66L, 73L, 72L, 
63L, 52L, 39L, 33L, 30L, 33L, 37L, 48L, 57L)), row.names = c(NA, 
-12L), class = c("tbl_df", "tbl", "data.frame"))